In industries where explosive or pressure testing may be necessary, it is common to build blast mitigation and protection systems around equipment to be pressure tested. In addition, there may be circumstances where equipment may be overspeed tested which may result in situations where flying objects of small to significant size and velocities up to 1000 feet per second are produced, thus also needing protection.
Similarly, in inherently dangerous industries where there is potential for dangerous explosions or blasts such as oil and gas exploration and production, blast mitigation and protection systems are commonly used to protect critical equipment from damage as well as to help mitigate serious bodily injury or death to well operators and other employees who must perform duties in and around the well. An example of such an inherently dangerous situation is high pressure equipment located on an offshore oil rig. During pressure testing of such equipment, application of a blast mitigation system is necessary in the event an explosive incident occurs.
Further still, there is a general need for explosive or blast protection for equipment or structures in light of various dangers that could pose a threat to these critical assets. All of these scenarios share a need for protection from the highly dangerous situations created by explosive blasts and the ensuing fragments and projectiles.
In the past, various patents have issued relating to apparatuses and methods for providing blast protection or containment utilizing various forms of blankets, tarps and other protective structures. Typically, such apparatuses utilize a modular system comprising a series of panels that are joined together in various fashions to form a unitary blast control blanket suitably sized for providing adequate protection of a critical piece of equipment. However, it is known in the art that such modular systems either suffer from bulky, cumbersome, and frustratingly inconvenient methods for joining various panels together. Such connection methods detract from the overall portability of the protection system, as assembly and disassembly may be time consuming for an operator and is more prone to incorrect assembly.
Furthermore, such prior art modular protection systems typically suffer from substantially weakened protection at the connection points themselves, as the connections are inevitably the weakest portion of an assembled blast control system.
For example, U.S. Pat. No. 3,491,847 to Abbott discloses an explosion cover which constitutes a protective pad adaptable to be secured to a vehicle. The pad includes an elongated sleeve enclosing a stack of flexible ballistic plastic textile material sheets. However, the cover described in Abbott is of a custom size and inconvenient in that the cover must be appropriately sized to the application to be used, and cannot be easily adapted to different size requirements without fabricating an entirely new cover from scratch. Furthermore, Abbott discloses the use of leather straps for extending from the pad for securing the pad to the equipment to be protected.
U.S. Pat. No. 3,870,256 to Mazzella teaches a wire net structure for heavy-duty use which comprises a rectangular mesh of diagonally intersecting wire elements framed by a peripheral cable passing through a set of eyes on each side of the rectangle. Mazzella further teaches that the wire net structure may be used as a blasting mat, several of which may be joined together adjacent one another around a conduit in danger of rupture, the meshing wire elements sliding freely past one another. However, the wire net structure disclosed in Mazzella is heavy and cumbersome to join, while also failing to provide sufficient blast protection in that the wire mesh may easily be penetrated with ballistic matter. Further, the method of joining various wire panels together in Mazzella results in weaker blast protection at the points where the wire net structures are connected to one another.
U.S. Pat. No. 4,590,714 to Walker discloses an insulating tarp made from two membranes which sandwich an insulating material made from fiber glass. The tarp contains a seam structure around all four edges of the tarp which not only fastens the two membranes together, but also holds the highly resilient insulating material in position. At least two adjacent edges of the tarp include a flap that extends along the seam structure along each of the edges. The edges include grommets at regular intervals used to interconnect several of the tarps together. However, the connectors and anchoring system for the tarp disclosed in Walker are substantially weaker than the tarp itself, and thus would fail in the event the tarp of Walker was used to contain large, high energy projectiles.
U.S. Pat. No. 8,006,605 to Tunis discloses a composite armor panel system that has a strike face assembly and a support and containment assembly joined by a bonding layer. The strike face assembly is formed of a hard material layer, which may be comprised of discrete elements or tiles, and a fiber reinforcement bonded to an inner and/or outer surface of the hard material layer which are encapsulated in a matrix material. The tiles and other materials are essentially joined together via a bonding layer which joins the strike face assembly to the support and containment assembly, and includes a mesh embedded in an adhesive material that minimizes cracks through the bonding layer. Thus, the armor system and connection method of Tunis, while suitable for rigid ballistic and blast resistant applications, is not flexible and relatively expensive.
Furthermore, other presently available systems for blast testing generally comprise a concrete bunker or pit built specifically for that purpose. Under this scenario, a pit is typically built for explosive or blast testing purposes and lined with reinforced concrete or block walls with an energy absorbing internal wall made of a material such as wood or steel panels. These concrete bunkers provide excellent protection against blasts and other explosive forces to be tested. However, such testing systems typically take a substantial amount of time and effort to design, and an even greater amount of time and expense to build. For instance, building such a concrete bunker requires significant expenditures to purchase and transport the building materials, as well as a lengthy period of time to physically build the bunker. Furthermore, some large equipment to be tested or protected would require an extremely large enclosure to be adequately tested, and such enclosures typically do not exist as the amount of time and money necessary to support their construction renders them prohibitively expensive and impractical.
In other cases, there may be a need for pressure or explosive testing at a logistically inconvenient work site requiring sufficient blast protection systems to be first installed, such as on a drilling platform. In such instances, it not suitable to install a permanent test structure such as a concrete testing bunker. Rather, there is a need for a blast protection system that may be quickly setup in a cost effective manner that may still provide adequate blast protection for the facility and personnel on site.
Thus, it can be seen that current technologies for ballistic and blast protection systems either provide insufficient protection for large scale blasts and explosions, or are inappropriate, heavy, and cost prohibitive when the structure or equipment to be protected becomes large. In particular, previously known modular blast protection systems suffer from cumbersome connection methods that are not easily assembled and provide substandard protection at the connection points, typically the weakest points of any blast protection system.
What is therefore needed is a relatively inexpensive, easily constructed blast protection system that is also lightweight and portable and therefore transportable for use in different locations. It is also desired that such a system be easily repairable if blast damages is sustained.